A cache memory has been used in order to improve performance of a program executing process. The cache memory is a high-speed memory which is installed in a central processing unit (CPU), or in a core of the CPU. The performance of the program executing process is improved by holding data having high reusability in the cache memory. Volume of the cache memory is smaller than that of a main memory. Accordingly, it is effective to hold the data having high reusability in the cache memory in order to increase a cache hit rate of the cache memory.
As a method of holding the data having high reusability in the cache memory, there is a cache memory having a sector function. In the cache memory having the sector function, a program indicates a sector storing data in accordance with the reusability of data. With this, there is a high possibility to hold the data having high reusability in the cache memory, thereby increasing the cache hit rate. The sector division ratio is set to be optimal.
A division control of the cache memory is disclosed in, for example, Japanese Laid-open Patent Publication No. 2009-163450, Japanese Laid-open Patent Publication No. 2010-244205, Japanese Laid-open Patent Publication No. 2011-203995, Japanese Laid-open Patent Publication No. 2004-030574, Japanese National Publication of International Patent Application No. 11-509356, and “SPARC64VIIIfx Extensions” (http: //img.jp.fujitsu.com/downloads/jp/jhpc/sparc64viiifx-extensions. pdf, http: //img.jp.fujitsu.com/downloads/jp/jhpc/sparc64viiifx-extensionsj.pdf).